So, the Phoenix reversing the ledger signifies a side on the rise - although there is a still a long way to go.
The Phoenix are still mired at the bottom of the table, one point behind the Central Coast Mariners, but they are only five points away from the Western Sydney Wanderers, who sit in the sixth and final playoff spot.
To get there, they'll need to keep up their current form, which has markedly improved after the mid-season additions of Matija Ljujic and Nathan Burns.
Those attacking signings had played the supersub role of the bench in their first two games, but both were inserted into the starting lineup, and they made a substantial difference.
Ljujic notched his second consecutive goal, though his effort was far more fortunate than last week's screamer. The Serbian midfielder went to put in a cross for Michael McGlinchey, who missed the header, but his run put Jets goalkeeper Jack Duncan in two minds, and the ball snuck past him into the bottom corner.
It was slightly against the run of play, after the Jets had previously butchered two big chances, with Phoenix custodian Lewis Italiano making a fantastic one-on-one save against Jason Hoffman as he bore down on goal.
Italiano was having a happier time than his counterpart, with Duncan soon picking the ball out of his net again. This time, he came for a Matt Ridenton corner, but got nowhere, with Daniel Mullen heading home to double the Phoenix's lead.
That lead held until just after halftime, when Andrew Nabbout nabbed one back for Newcastle, but Roy Krishna returned the favour 10 minutes later. Burns set him up with a run down the left, before the Fijian finished adroitly with a right-footed curler into the corner.
The Jets kept things tense as Dimitri Petratos converted an 86th minute penalty after a video referee consultation, and they went upstairs in injury time for another penalty shout, which was waved away.
Eventually, the Phoenix held on for a potentially season-changing victory.
Newcastle Jets 2 (Nabbout, Petratos goals)
Wellington Phoenix 3 (Ljujic, Mullen, Krishna goals)
HT: 0-2